1 MEMORANDUM

Subject: Analysis of the Types of Engines Used to Estimate the CAA Section 112(k) Area Source Inventory for Stationary Recipr ocating Internal Combustion Engines

From: Melanie King, Energy Strategies Group

To: EPA Docket EPA-HQ-OAR-2008-0708

Date: December 21, 2009

Section 112(c)(3) of the Clean Ai r Act (CAA) requires that EPA lis t categories or subcategories

of area sources sufficient to ensure that area s ources representing 90 perc ent of the area source emissions of the 30 HAP that presen t the greatest threat to public health in the largest number of urban areas are regulated. EPA listed the stationary reciproca ting internal combustion engine area source category under 112(c)(3) and (k) as one of the categorie s needed to ensure that 90 percent of such area source emissions are regulat ed. In response to comments received on the proposed NESHAP for existing stationary RICE located at area sources (74 FR 9697), EPA analyzed the types of engines th at were included in the area sour ce category listing for stationary RICE. As a result of this analysis, EPA dete rmined that emissions from existing stationary emergency engines located at residential, co mmercial, and institutional facilities were not included in the 1990 baseline emissions inventory th at was used as the basis for the listing of source categories needed to ensure that 90 pe rcent of area source emissions are regulated. 1

Residential, commercial, and institutional area sour ce sectors comprise of housing units; wholesale and retail businesses; health institutio ns; social and educational institutions; and Federal, state, and local government institut ions (e.g., military installations, prisons, office buildings). Therefore, EPA determined that thes e engines at these locations will not be subject

to this area source standard. A detailed description of the analysis to determine the engines that were the basis for the inventory is provided below.

Summary of the information used in estima ting the 1990 112(k) Area Source Inventory for Stationary RICE

The emissions for stationary RICE used to estim ate the 1990 112(k) area source inventory were calculated using national estimates for fuel consum ption (in units of J/ yr) of natural gas and distillate oil for engine s used for two purposes: 1) engines used by utilities for electricity generation 2) engines used in industrial applications

EPA extrapolated fuel consumption inform ation for the year 1990 from estimates of consumption for the years 1978 and 1985 in an EPA report (Reference 1). The 1990 fuel

1 1990 Emissions Inventory of Forty Potential Section 112(k) Pollutants, Supporting Data for EPA’s Section 112(k) Regulatory “Strategy. May 21, 1999.2 consumption estimates were multiplied by a J/Btu conversion and then multiplied by a

lb/MMBtu emission factor in order to determine the tons emitted per year for each HAP. This was done for each fuel type (natur al gas and distillate oil).

The EPA report does not have any further descripti on of what type of engines are included in the fuel consumption data. The EPA- RTP Library was able to obtain so me of the references for the fuel consumption data. None of the references have any information on what size of engines are included. The primary references for the 1978/1 985 data for the engines used by utilities for electricity generation do not provi de any additional detail about wh at engines are included. The reference for the 1978 data for the engines used in industrial applications i ndicates that the data is for engines used for the following applications:

• oil and gas pipelines

• natural gas processing plants

• oil and gas exploration

• crude oil production

• natural gas production

• agricultural

• industrial process

• municipal water and sewage

The Library was unable to obtai n the reference for the 1985 data for industrial application engines.

Detailed description of fuel consumption data

The fuel consumption numbers that were used are shown in Table 1. The 1978 and 1985 fuel consumption data were obtaine d from Reference 1. EPA extrapolated the estimates for 1990
from the 1978 and 1985 estimates.

Table - Fuel consumption (10 15 J/yr) for stationary reciprocating engines Year Engines used for electricity generation Engines used in industrial applications

Natural Gas Distillate Oil Natural Gas Distillate Oil

1978 25 a 31 a 1004 d 62 d

1985 15 b 43 b 1093 e 73 e

1990 26 c 34 c 1171 f 72 f

a The 1978 fuel consumption numbers were dete rmined by subtracting National Electric Reliability Council (NERC) estimates of 1976 fuel c onsumption for utility turbines (Reference 2) from Federal Power Commission (FPC) data for 1976 fuel consumption by internal combustion plants owned by utilities (Refer ence 3). The 1978 fuel consump tion for electricity generation reciprocating engines was assumed to be equa l to the 1976 numbers “as reciprocating engine generating capacity for the tw o years are about equal.”

b The 1985 fuel consumption estimates for reciproca ting engines used by util ities for electricity generation were determined using NERC estimat ed fuel requirements for 1985 (Reference 2).3 The NERC estimates were for fuel consumpti on for combustion turbines. The 1985 estimates were a 40.8% decrease in fuel consumption for ga s-fueled turbines from the 1978 figures. The EPA report estimated that the fuel consumption for natural gas-fired engines would decrease by the same percentage as for turbines (40.8%). Based on estimates from the FPC (Reference 4), the EPA report estimated that the total diesel engine capacity would increase by 2.1% from 1976-1985. The fuel consumption for distillate-f ired engines would therefore increase by 37.2% from 1978 to 1985 due to the increased capacity a nd the decreased consumption of natural gas.

c The 1990 consumption estimates were “assumed” by Fred Porter of EPA and it doesn’t say how

he “assumed” those numbers.

d The 1978 fuel consumption data for industr ial engines was estimated from 1971 fuel consumption data from an EPA report (Reference 5) and the ratios of domestic natural gas and crude oil production figures for those two years (References 6-8). The 1971 fuel consumption data was for engines used in the following applications: Application Engine uses listed for application Oil and gas pipelines

Natural gas processing plants drive gas compressors and refrigeration

compressors Oil and gas exploration drive electr ic generators, drawworks, drilling mud pumps, rotary drilling rigs Crude oil production drive beam pumps, gas lift compressors, hydraulic pump power pumps Natural gas production driv e repressuring compressors Agricultural drive agricultural water pumps

Industrial process drive industrial process equipment and plant air compressors Municipal water and sewage drive municipal water and sewage pumps

e Projected 1985 fuel consumption rates for industr ial internal combustion sources were estimated based on 1985 domestic natural gas and crude oil supply rates from the Federal Energy Administration (Reference 8). Assumptions used are that fuel consumption rates are proportional to domestic natural gas production and th at fuel consumption rates for distillate oil fueled engines are proportional to domestic crude oil production. Exception is that fuel consumed by gas reciprocating engines for crude oil production is assumed to be proportional to the domestic crude oil production rate.

f Fuel consumption for 1990 was extrapolated for i ndustrial engines assuming that the growth rate in fuel consumption from 1978 to 1985 was the sa me as the growth rate from 1985 to 1990. A compound growth rate was assumed. Distribu tion between gas and oil fired engines was
assumed to be the same in 1990 as in 1978.4 References

1. Emissions Assessment of Conventional Stationary Combustion Systems: Volume II. Internal

Combustion Sources. EPA-600/ 7-79-029c. February 1979.

2. Fossil and Nuclear Fuel for El ectric Utility Generation Requi rements and Constraints. 1977-
1986. National Electric Relia bility Council, Princeton, New Jersey. August 1977.

3. FPC News Release No. 23009. Federal Power Commission, Washington, D.C. March 25,

1977.

4. FPC News Release No. 22673. Federal Power Commission, Washington, D.C. October 15,

1976.

5. McGowin, C.R. Stationary Internal Combus tion Engines in the United States. Report prepared by the Shell Development Co. for the U.S. Environmental Protection Agency. EPA Report No. R2-73-210. April 1973. 120 p. NTIS PB-221 457.

6. 1974 Gas Facts. American Gas Association. Arlington, VA. 1975.

7. Dupres, W.G., Jr. and J.S. Corsentino. United States Energy through the Year 2000 (Revised) Bureau of Mines, U.S. Depa rtment of the Interior. December 1975.

8. National Energy Outlook, Federal Ener gy Administration. February 1976.